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Metanx is currently classified as a food supplement indicated for blood vessel dysfunction, elevated homocysteine- especially in those patients for high risk for atherosclerotic coronary, peripheral or cerebral vessels, B6 B12 vitamin deficiencies and neuropathy. For purposes of this article, the indication for neuropathy will be discussed.


Its role in neuropathy, the reduction of nerve pain, is due to its reduction of homocysteine which is pathologic to both the vascular tree and the nerve tissue. The mechanism is accomplished by the three ingredients in Metanx.

-L-methyfolate is the active form of folate in the body’s circulation transported across cell membranes into the peripheral tissues and across the blood brain barrier. It increases the availability of nitric oxide which lowers the detrimental homocysteine that produces toxic effects by oxidation of nerve cells, thus improving endothelial(blood vessel wall lining) and integrity of the nerve cells, reducing detrimental destruction and improving neuropathy symptoms.

-Methylcobalamin is one of two forms of active B12 and is absorbed into the small intestine by a transport facilitator-intrinsic factor. Cobalamin facilitates the production of healthy nerve cell wall protection (myelinogenesis) and healthy nerve regeneration. It also serves to address possibilities of pernicious anemia.

-Pridoxal phosphate is the active form of B6 which is necessary for the healthy function of the nervous system.

Though presently considered a prescription food supplement, drug interactions due exist.

Parkinson patients taking levodopa should avoid this medication due to the B6 component which will antagonize the levodopa. Those patients taking the combination L-dopa/carbidopa prescription need not avoid Metanx. Epileptic patients taking phenytoin (Dilantin) may have a decrease in its effectiveness


The usual dose is one tablet twice daily, is available only by prescription and supplied as a coated purple tablet with L-methyfolate 2.8mg, Pridoxal phosphate (B6) 25mg and Methylcobalamin (B12) 2mg.

The prevalence of diabetes mellitus is constantly increasing with approximately 8 % of the US population diagnoses with another 8-10 million non diagnosed. On the average 60% of the diabetics experience diabetic peripheral neuropathy (DPN). Studies reveal that after approximately 6months, patients treated with Metanx 82% of the patients noted a reduction in both reduced frequency and intensity of the severe pain of neuropathy.


Metanx, the Next Generation of Homocysteine Therapy, Merck KGaA, Germany, 2005

MPR, Monthly Prescribing Reference, Pain Edition 2011.

Reviews in Neurological Diseases, vol 8/ number 1 / 2, 2011.


My personal practice with Metanx is very favorable. Along with a topical, Diabetiderm, (arginine) cream, it is my first line of treatment for the neuropathic patient and find that patients achieve relief from the painful symptoms of neuropathy. Due to the beneficial effects of both the pyridoxal phosphate and methylcobalamin are essential to nerve function damaged by diabetes and actually increasing the concentration of epidermal (skin) nerve fiber density with is diminished with diabetes.

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